The main purpose of free "Prevent Restore" program is to make deleted files and folders unrecoverable. Its made as Wizard program and will be friendly for any computer newbie. "Prevent Restore" will overwrite all free space on your hard disks that can contain fragments of deleted files with random data to avoid any possibility of recovery. It uses several security algorithms (you can replace deleted data with random characters, digits, spaces e.t.c.). While writing "Prevent Restore" fills out information to the end of each cluster, leaving no chance to restore even just one word!
Because your hard disk free space can be over hundred Gigs, complete anti-recovery process can take a while. For example, up to one hour or even more on a large disk free space. Its normal. You can leave "Prevent Restore" and it will turn off computer when done. There is also built-in option to prevent computer from StandBy mode to make sure all operations will be complete.
Is it safe? Sure! This utility doesnt make any harm to existing files.